Jan. 8 , 2014: HWP has created this document to explain the differences between the 2004 Risk-Based Corrective Action Process for Petroleum Storage Tanks guidance document and the 2013 update of the guidance. The document is nearly comprehensive, excluding only a few minor, non-substantive grammatical corrections. Questions regarding changes to the Tanks RBCA guidance document should be directed to Tim Chibnall of HWP.

Oct. 17, 2013: The Hazardous Waste Management Commission gave final approval to the department’s amendments of 10 CSR 26-2.062, 2.078, and 2.082 and the Risk-Based Corrective Action Process for Petroleum Storage Tanks guidance document updated in 2013. The guidance update included changes to the Tier 1 Risk-Based Target Levels (RBTLs). The rule amendments were necessary to, in part, incorporate the updated Tanks RBCA guidance into rule by reference. The updated guidance is dated Oct. 17, 2013. The amended rules will become effective on Feb. 28, 2014.

The department developed this document to explain which version of the Risk-Based Corrective Action Process for Petroleum Storage Tanks guidance document owners and operators and their consultants may use before and after the amended rules and updated guidance document become effective.

Sept. 17, 2013: Under the RBCA process, activity and use limitations (AULs) may be used as part of a corrective action plan to address risks associated with a petroleum storage tank release. To promote consistency and efficiency in the application of AULs, the department has developed model activity and use limitations and one and two-party restrictive covenants. The model documents are available below under the heading “Activity and Use Limitations.”

June 3, 2011: The following pertains to the 2004 RBCA guidance, but not to the 2013 RBCA guidance. The department issued an errata notice pertaining to the April 2005 version of Table 4-1, Soil Concentration Levels to Determine the Need for Groundwater Evaluation During Tank Closure, of the RBCA guidance. The notice concerns incorrect target levels in the table pertaining to TPH-GRO, TPH-DRO, C6-C8 Aliphatics, C8-C10 Aliphatics, C10-C12 Aliphatics and C12-C16 Aliphatics.

Nov. 6, 2009: The following pertains to the 2004 RBCA guidance; the conversion factor has been corrected in the 2013 RBCA guidance. The department issued an errata notice pertaining to Appendix D of the January 2004 guidance. The notice concerns an incorrect conversion factor in the Appendix.

Activity and Use Limitations

Sections 6.9 and 11 of the MRBCA Process for Petroleum Storage Tanks guidance document (both the 2004 and 2013 versions) allow for the use AULs as part of a corrective action plan (CAP) for a petroleum storage tank release. CAPs must be submitted to the department for review and approval.

The department evaluates each such proposal on a case-by-case basis to determine whether the proposed AUL is technically and legally sufficient to manage or eliminate unacceptable risk associated with a release. If the department approves the use of a restrictive covenant as part of a CAP, it must be properly recorded in the property’s chain of title before the department will issue a no further action letter for that release.

While the department prefers the use of two-party covenants signed by both the landowner and the department, other formats may be used. Please note that a two-party covenant would enable the department to ensure future landowners comply with the restriction(s), which may reduce the risk of future noncompliance and may reduce the risk of further action needing to be used in the future by the tank owner or operator from whose tanks the release occurred.

Model documents are provided below. To help tank owners and operators and other parties complete the covenants, and to hasten the department’s review and approval of completed covenants, the model documents below have been color-coded, as follows:

Sections highlighted in yellow must be filled in using site-specific information that will be different for every site.

Sections highlighted in green may be changed if warranted.

Changes to the sections highlighted in gray should be made rarely and only when justifiable; any changes to these sections will require review by department legal counsel, may be found to be unacceptable, and will very likely significantly delay department approval of the covenant.

NOTE: If applying the Oct. 17, 2013 version of the Tanks RBCA guidance, Tier 2 site-specific target levels, if developed, must be calculated by the person conducting the evaluation using the updated equations and input values found in Appendix B or by using the MRBCA Computational Software for Petroleum Storage Tanks Version 3.0 dated February 2014. Earlier versions of the software shall not be used with the updated guidance. Version 3.0 of the software is available from the RAM Group by calling 713-784-5151.

Note: When opening the Tier 1 - 2 Excel files, a series of dialogues will be presented.Click OK if "missing file" warnings appear, there are no missing files Click Enable Macros when given the option. Several functions of the forms use macros.Click No when asked to update links, there are no external links to update.

Note: The risk-based target levels that appear on forms Tier 1-12(1) through Tier 1-12(10) are not current and, therefore, the forms should not be used as part of a risk assessment report. Alternatively, forms Tier 2-2(1) through Tier 2-2(10) or a table or spreadsheet of your own construction may be used for Tier 1 reporting. To use the Tier 2-2 forms at Tier 1, enter both a representative concentration and a current, soil type dependent risk-based target level on the forms. Cross through the form number in the upper right corner and write in the corresponding Tier 1 form number (e.g., Tier 1-12(1)).